by Rick Jervis, USA TODAY

by Rick Jervis, USA TODAY

Gun control advocates hope a National Rifle Association's announcement Friday will nudge national laws toward making it harder to gain access to some semi-automatic weapons, such as the ones used by the gunman in the Newtown, Conn., school massacre.

One step the NRA may take: back recent efforts to include mental health records in national background checks by federally licensed gun dealers, said John Rosenthal, co-founder of the Newton, Mass.- based Stop Handgun Violence.

But that would not address the thousands of rifles and handguns sold each year by private dealers at gun shows and elsewhere in 33 states where background checks are not required by unlicensed sellers, Rosenthal said.

The NRA, a powerful lobbying force that supports gunmakers and owners, backed a similar proposal to include mental health records in background checks following the 2007 Virginia Tech shooting, where a gunman shot and killed 32 people in the deadliest shooting incident by a single gunman in U.S. history, he said. That initiative never made it out of Congress.

The NRA, National Shooting Sports Foundation and National Association for Gun Rights did not return requests for comments for this story.

Calls to tighten gun control often surface after mass shootings. But the outcry has been noticeably stronger in the wake of last week's shooting, where gunman Adam Lanza, 20, shot and killed 20 children and six adults using a semi-automatic rifle at an elementary school in Connecticut.

The Connecticut incident may trigger a change in the NRA's policy toward gun control, said Jon Vernick of the Johns Hopkins Center for Gun Policy and Research. "This shooting has certainly felt like a game-changing moment," Vernick said.

One of the most significant changes would be requiring universal background checks for all gun sales, not just by sanctioned gun dealers, he said. Around 40% of all gun sales are made by private dealers, he said.

President Obama on Wednesday announced the formation of an interagency task force, led by Vice President Biden, looking at gun control and other measures to prevent a repeat of the massacre in Connecticut. During the announcement, Obama called for renewing the 1994 assault-weapons ban, which expired in 2004, as well as stricter background checks and limiting high-capacity magazines.

"The fact that this problem is complex can no longer be an excuse for doing nothing," Obama said. "The fact that we can't prevent every act of violence doesn't mean we can't steadily reduce the violence."

In the wake of the Connecticut shootings, the NRA went uncharacteristically quiet, even shutting down its Facebook page. On Tuesday, it released a statement saying the organization had kept silent "out of respect for the families, and as a matter of common decency" and promised to reveal "meaningful contributions" to prevent a repeat of the shootings.

Despite the increased outcry following the recent shootings, there's little hope that Congress will enact meaningful gun control legislation without the NRA's blessing, Rosenthal said.

"Nothing will go through the House of Representatives under Republican leadership without the NRA," he said.